Use of cannabinoids in the treatment of epilepsy

ABSTRACT

The present invention relates to the use of cannabidiol (CBD) in the treatment of focal seizures. In one embodiment the patients suffering from focal seizures are children and young adults. CBD appears particularly effective in reducing focal seizures in patients suffering with etiologies that include: Lennox-Gastaut Syndrome; Tuberous Sclerosis Complex; Dravet Syndrome; CDKL5; Neuronal ceroid lipofuscinoses (NCL); febrile infection related epilepsy syndrome (FIRES); Aicardi syndrome and brain abnormalities in comparison to other seizure types. Significantly CBD additionally is very effective in the reduction of a sub-type of focal seizures, focal seizures with impairment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to UK 1510664.4, filed Jun. 17, 2015.

FIELD OF THE INVENTION

The present invention relates to the use of cannabidiol (CBD) in thetreatment of focal seizures. In one embodiment the patients sufferingfrom focal seizures are children and young adults. CBD appearsparticularly effective in reducing focal seizures in patients sufferingwith etiologies that include: Lennox-Gastaut Syndrome; TuberousSclerosis Complex; Dravet Syndrome; CDKL5; Neuronal ceroidlipofuscinoses (NCL); febrile infection related epilepsy syndrome(FIRES); Aicardi syndrome and brain abnormalities in comparison to otherseizure types.

Significantly CBD additionally is very effective in the reduction of asub-type of focal seizures, focal seizures with impairment. Theetiologies of patients which suffer from focal seizures with impairmentinclude: Lennox-Gastaut Syndrome; Tuberous Sclerosis Complex; DravetSyndrome; CDKL5; febrile infection related epilepsy syndrome (FIRES);Aicardi syndrome and brain abnormalities.

In these patients treatment with CBD reduced the occurrence of absenceseizures or myoclonic absence seizures by greater than 50% in a largeproportion of patients, 64% and 75% respectively. This was surprisinggiven that the proportion of patients benefitting from a greater than50% reduction in total seizures was significantly less, (46%), in allsubjects treated.

Preferably the CBD used is in the form of a highly purified extract ofcannabis such that the CBD is present at greater than 98% of the totalextract (w/w) and the other components of the extract are characterised.In particular the cannabinoid tetrahydrocannabinol (THC) has beensubstantially removed, to a level of not more than 0.15% (w/w) and thepropyl analogue of CBD, cannabidivarin, (CBDV) is present in amounts ofup to 1%. Alternatively, the GBD may be a synthetically produced CBD.

In use the CBD may be used concomitantly with one or more otheranti-epileptic drugs (AED). Alternatively the CBD may be formulated foradministration separately, sequentially or simultaneously with one ormore AED or the combination may be provided in a single dosage form.Where the CBD is formulated for administration separately, sequentiallyor simultaneously it may be provided as a kit or together withinstructions to administer the one or more components in the mannerindicated. It may also be used as the sole medication, i.e. as amonotherapy.

BACKGROUND TO THE INVENTION

Epilepsy occurs in approximately 1% of the population worldwide,(Thurman at al., 2011) of which 70% are able to adequately control theirsymptoms with the available existing anti-epileptic drugs (AED).However, 30% of this patient group, (Eadie et al., 2012), are unable toobtain seizure freedom using the AED that are available and as such aretermed as suffering from intractable or “treatment-resistant epilepsy”(TIRE).

Intractable or treatment-resistant epilepsy was defined in 2009 by theInternational League Against Epilepsy (ILAE) as “failure of adequatetrials of two tolerated and appropriately chosen and used AED schedules(whether as monotherapies or in combination) to achieve sustainedseizure freedom” (Kwan at al., 2009).

Individuals who develop epilepsy during the first few years of life areoften difficult to treat and as such are often termedtreatment-resistant. Children who undergo frequent seizures in childhoodare often left with neurological damage which can cause cognitive,behavioral and motor delays.

Childhood epilepsy is a relatively common neurological disorder inchildren and young adults with a prevalence of approximately 700 per100,000. This is twice the number of epileptic adults per population.

When a child or young adult presents with a seizure, investigations arenormally undertaken in order to investigate the cause. Childhoodepilepsy can be caused by many different syndromes and genetic mutationsand as such diagnosis for these children may take some time.

The main symptom of epilepsy is repeated seizures. In order to determinethe type of epilepsy or the epileptic syndrome that a patient issuffering from, an investigation into the type of seizures that thepatient is experiencing is undertaken. Clinical observations andelectroencephalography (EEG) tests are conducted and the type(s) ofseizures are classified according to the ILAE classification describedbelow and in FIG. 1.

The International classification of seizure types proposed by the ILAEwas adopted in 1981 and a revised proposal was published by the ILAE in2010 and has not yet superseded the 1981 classification. FIG. 1 isadapted from the 2010 proposal for revised terminology and includes theproposed changes to replace the terminology of partial with focal. Inaddition the term “simple partial seizure” has been replaced by the term“focal seizure where awareness/responsiveness is not impaired” and theterm “complex partial seizure” has been replaced by the term “focalseizure where awareness/consciousness is impaired”.

From FIG. 1 it can be seen that Generalised seizures, where the seizurearises within and rapidly engages bilaterally distributed networks, canbe split into six subtypes: Tonic-Clonic (grand mal) seizures; Absence(petit mal) Seizures; Clonic Seizures; Tonic Seizures; Atonic Seizuresand Myoclonic Seizures.

Focal (partial) seizures where the seizure originates within networkslimited to only one hemisphere, are also split into sub-categories. Herethe seizure is characterized according to one or more features of theseizure, including aura, motor, autonomic and awareness/responsiveness.Where a seizure begins as a localized seizure and rapidly evolves to bedistributed within bilateral networks this seizure is known as aBilateral convulsive seizure, which is the proposed terminology toreplace Secondary Generalized Seizures (generalized seizures that haveevolved from focal seizures and are no longer remain localized).

Focal seizures where the subjects awareness/responsiveness is alteredare referred to as focal seizures with impairment and focal seizureswhere the awareness or responsiveness of the subject is not impaired arereferred to as focal seizures without impairment.

Focal seizures may occur in epilepsy syndromes including: Lennox-GastautSyndrome; Tuberous Sclerosis Complex; Dravet Syndrome; CDKL5: Neuronalceroid lipofuscinoses (NCL); febrile infection related epilepsy syndrome(FIRES); Aicardi syndrome and brain abnormalities.

Epileptic syndromes often present with many different types of seizureand identifying the types of seizure that a patient is suffering from isimportant as many of the standard AED's are targeted to treat or areonly effective against a given seizure type/sub-type.

One such childhood epilepsy is Dravet syndrome. Onset of Dravet syndromealmost always occurs during the first year of life with clonic andtonic-clonic seizures in previously healthy and developmentally normalinfants (Dravet, 2011). Symptoms peak at about five months of age. Otherseizures develop between one and four years of age such as prolongedfocal dyscognitive seizures and brief absence seizures.

In diagnosing Dravet syndrome both focal and generalised seizures areconsidered to be mandatory, Dravet patients may also experience atypicalabsence seizures, myoclonic absence seizures, atonic seizures andnon-convulsive status epilepticus.

Seizures progress to be frequent and treatment-resistant, meaning thatthe seizures do not respond well to treatment. They also tend to beprolonged, lasting more than 5 minutes. Prolonged seizures may lead tostatus epilepticus, which is a seizure that lasts more than 30 minutes,or seizures that occur in clusters, one after another.

Prognosis is poor and approximately 14% of children die during aseizure, because of infection, or suddenly due to uncertain causes,often because of the relentless neurological decline. Patients developintellectual disability and life-long ongoing seizures. Intellectualimpairment varies from severe in 50% patients, to moderate and mildintellectual disability each accounting for 25% of cases.

There are currently no FDA approved treatments specifically indicatedfor Dravet syndrome. The standard of care usually involves a combinationof the following anticonvulsants: clobazam, clonazepam, levetiracetam,topiramate and valproic acid.

Stiripentol is approved in Europe for the treatment of Dravet syndromein conjunction with clobazam and valproic acid. In the US, stiripentolwas granted an Orphan Designation for the treatment of Dravet syndromein 2008; however, the drug is not FDA approved.

Potent sodium channel blockers used to treat epilepsy actually increaseseizure frequency in patients with Dravet Syndrome. The most common arephenytoin, carbamazepine, lamotrigine and rufinamide.

Management may also include a ketogenic diet, and physical and vagusnerve stimulation. In addition to anti-convulsive drugs, many patientswith Dravet syndrome are treated with anti-psychotic drugs, stimulants,and drugs to treat insomnia.

The first line treatment for focal seizures are AED such ascarbamezapine or lamotrigine. Levetiracetam, oxycarbamezapine or sodiumvalproate are also considered to be of use. A combination of thesemedicaments may be required in order to treat focal seizures.

Common AED defined by their mechanisms of action are described in thefollowing tables:

TABLE 1 Examples of narrow spectrum AED Narrow- spectrum AED MechanismIndication Phenytoin Sodium channel Complex partial Tonic-clonicPhenobarbital GABA/Calcium channel Partial seizures Tonic-clonicCarbamazepine Sodium channel Partial seizures Tonic-clonic Mixedseizures Oxcarbazepine Sodium channel Partial seizures Tonic-clonicMixed seizures Gabapentin Calcium channel Partial seizures Mixedseizures Pregabalin Calcium channel Adjunct therapy for partial seizureswith or without secondary generalisation Lacosamide Sodium channelAdjunct therapy for partial seizures Vigabatrin GABA Secondarilygeneralized tonic- clonic seizures Partial seizures Infantile spasms dueto West syndrome

TABLE 2 Examples of broad spectrum AED Broad- spectrum AED MechanismIndication Valproic acid GABA/Sodium channel First-line treatment fortonic- clonic seizures, absence seizures and myoclonic seizuresSecond-line treatment for partial seizures and infantile spasms.Intravenous use in status epilepticus Lamotrigine Sodium channel Partialseizures Tonic-clonic Seizures associated with Lennox-Gastaut syndromeEthosuximide Calcium channel Absence seizures Topiramate GABA/Sodiumchannel Seizures associated with Lennox-Gastaut syndrome ZonisamideGABA/Calcium/Sodium Adjunctive therapy in adults channel withpartial-onset seizures Infantile spasm Mixed seizure Lennox-Gastautsyndrome Myoclonic Generalised tonic-clonic seizure LevetiracetamCalcium channel Partial seizures Adjunctive therapy for partial,myoclonic and tonic-clonic seizures Clonazepam GABA Typical and atypicalabsences Infantile myoclonic Myoclonic seizures Akinetic seizuresRufinamide Sodium channel Adjunctive treatment of partial seizuresassociated with Lennox-Gastaut syndrome

TABLE 3 Examples of AED used specifically in childhood epilepsy AEDMechanism Indication Clobazam GABA Adjunctive therapy in complex partialseizures Status epilepticus Myoclonic Myoclonic-absent Simple partialComplex partial Absence seizures Lennox-Gastaut syndrome StiripentolGABA Severe myoclonic epilepsy in infancy (Dravet syndrome)

From these tables it can be seen that there are many AED are approvedfor use in focal (partial) seizures which work by a differentmechanisms. Indeed the only AED that has been approved for use in thetreatment of complex partial seizures (focal seizures with impairment)is the AED phenytoin.

Over the past forty years there have been a number of animal studies onthe use of the non-psychoactive cannabinoid cannabidiol (CBD) to treatseizures. For example, Consroe et al., (1982) determined that GBD wasable to prevent seizures in mice after administration of pro-convulsantdrugs or an electric current.

Studies in epileptic adults have also occurred in the past forty yearswith CBD. Cunha et al. reported that administration of CBD to eightadult patients with generalized epilepsy resulted in a marked reductionof seizures in 4 of the patients (Cunha of al., 1980).

A study in 1978 provided 200 mg/day of pure CBD to four adult patients,two of the four patients became seizure free, whereas in the remainderseizure frequency was unchanged (Mechoulam and Carlini, 1978).

In contrast to the studies described above, an open label study reportedthat 200 mg day of pure CBD was ineffective in controlling seizures intwelve institutionalized adult patients (Ames and Cridland, 1986).

Based on the fact that chronologically the last study to look at theeffectiveness of CBD in patients with epilepsy proved that CBD wasunable to control seizures, there would be no expectation that CBD mightbe useful as an anti-convulsant agent.

In the past forty years of research there have been over thirty drugsapproved for the treatment of epilepsy none of which are cannabinoids.Indeed, there appears to have been a prejudice against cannabinoids,possibly due to the scheduled nature of these compounds and/or the factthat THC, which is a known psychoactive, has been ascribed as apro-convulsant (Consroe et al., 1977).

A paper published recently suggested that cannabidiol-enriched cannabismay be efficacious in the treatment of epilepsy. Porter and Jacobson(2013) report on a parent survey conducted via a Facebook group whichexplored the use of cannabis which was enriched with CBD in childrenwith treatment-resistant epilepsy. It was found that sixteen of the 19parents surveyed reported an improvement in their child's epilepsy. Thechildren surveyed for this paper were all taking cannabis that waspurported to contain CBD in a high concentration although the amount ofCBD present and the other constituents including THC were not known formany of the cases. Indeed, whilst CBD levels ranged from 0.5 to 28.6mg/kg/day (in those extracts tested), THC levels as high as 0.8mg/kg/day were reported.

Providing children with TRE with a cannabis extract that comprises THC,which has been described as a pro-convulsant (Consroe et al., 1977), ata potentially psychoactive dose of 0.8 mg/kg/day, is a concern and assuch there is a need to determine whether CBD is in fact efficacious.

In November 2013 the company GW Pharmaceuticals made a press release tostate that they were intending to treat Dravet Syndrome with CBD as ithad received orphan drug designation. A further press release was madein June 2014 which stated promising signals of efficacy in children withtreatment-resistant epilepsy, including patients with Dravet syndrome.

The international patent application WO 2015/193667 describes the use ofCBD in treatment resistant epilepsy. Patients included nine with Dravetsyndrome out of 27 others.

The international patent application WO 2015/193668 describes the use ofCBD in the treatment of absence seizures, Patients included those withDravet syndrome in addition to ten other syndromes.

Maa and Figi (2014) discuss the case for medical marijuana in epilepsyand discuss the positive treatment of a girl Charlotte with Dravetsyndrome who experienced frequent bouts of febrile and afebrile statusepilepticus as well as tonic, tonic-clonic and myoclonic seizures(generalised seizures). She was given an extract from a cannabis plantdubbed “Charlotte's Web” which according to the suppliers, CWBotanicals, disclose that their extracts are rich in terpenes andcontain from 10 to 200 times the amount found in other proprietaryplants. In other words the suggestion is that the efficacy is based on acombination of CBD and the terpenes present in their extracts.

Press et al. (3 Apr. 2015), provides an in depth review of the parentalreporting of pediatric patients with refractory epilepsy that were givenoral cannabis extracts (OCE). Despite its in depth nature it concludesno studies demonstrate clear efficacy.

Significantly the document recognizes the effectiveness of ananti-seizure medication may be dependent upon: the drug itself,including CBD, (see Table 3); the epilepsy syndrome type (Table 2); andthe seizure type (Table 2).

Very significantly the document in the discussion recognises cautionneeds to be taken when reviewing, particularly open label study data,since placebo rates may be high. Indeed it specifically comments that“four recently FDA approved anti-convulsant medications had placeborates of 31.6%, 26.4%, 20% and 21% respectively” (page 51, left handcolumn).

Furthermore the analysis observed a surprising finding namely that “newresidents of Colorado (those moving to obtain treatment) were more thanthree times as likely to report a greater than 50% seizure reductionthan families with established care in Colorado” suggestive that studiessuch as that published in Porter and Jacobson (2013) may be highlyflawed.

The skilled person would infer therefore from Press et al. would be thatthe drug type CBD plus the presence of “other OCE” (such as, othercannabinoids most likely THC and non-cannabinoids such as e.g. terpenes)appears a more interesting combination than CBD alone—responder rate 63%versus 35%.

That the epilepsy syndrome Lennox-Gastaut appears the most promisingtarget with 89% responder rate versus Dravet (23% responder rate) orDoose (0% responder rate).

That of the seizure types studied ranged from 44% responder rate foratonic seizures to 17% responder rates in tonic seizures, amongst theseven seizures types reviewed.

The assessment looked at three distinct groups, namely; the OCE type,Table 3 (four OCE types); the epilepsy syndrome, see for example, page50 right hand column line 3 (three syndrome types); and the seizuretype, see page 51, Table 2 (seven seizure types).

In all this provides the reader with information on 84 differentalternative combinations.

The problem facing the skilled practitioner looking at cannabismedicines in the field of epilepsy where many patients are refractory toexisting medications is to select the appropriate cannabinoid and itsform targeted to a given seizure type in a given patient group.

Perhaps therefore it is not surprising that in the Cochrane report(Gloss and Vickrey) published March 2014 undertook a full review on theefficacy of cannabinoids in the treatment of epilepsy concluded “noreliable conclusions can be drawn at present regarding the efficacy ofcannabinoids as a treatment for epilepsy.”

Surprisingly the applicant has shown that CBD is particularly effectivein the treatment of focal seizures in Dravet syndrome patients,particularly children and more particularly those which are resistant toexisting treatments.

BRIEF SUMMARY OF THE DISCLOSURE

In accordance with a first aspect of the present invention there isprovided Cannabidiol (CBD) for use in the treatment of focal seizures inDravet Syndrome.

In one embodiment the focal seizures are focal seizures with impairment.

Preferably the Dravet Syndrome is treatment-resistant.

In a further embodiment the CBD is for use in combination with one ormore concomitant anti-epileptic drugs (AED).

In a further embodiment the CBD is present as a highly purified extractof cannabis which comprises at least 98% (w/w) CBD. Preferably theextract comprises less than 0.15% THC. More preferably the extractfurther comprises up to 1% CBDV.

In an alternative embodiment the CBD is present as a synthetic compound.

In a further embodiment of the invention the one or more AED is selectedfrom the group consisting of: carbamezapine, clobazam, clonazepam,clonidine, clorazepate, desmethylclobazam, diazepam, ethosuximide,felbamate, ketogenic diet, lacosamide, lamotrigine, levetiracetam,lorazepam, midazolam, N-desmethylclobazam, nordiazepam,oxycarbamezapine, perampanel, phenobarbital, phenytoin, pregabalin,rufinamide, stiripentol, topiramate, trazodone, vagus nerve stimulation,valproic acid, vigabatrin, and zonisamide.

Preferably the number of different anti-epileptic drugs that are used incombination with the CBD is reduced. Alternatively the dose ofanti-epileptic drugs that are used in combination with the CBD isreduced.

There are many side effects associated with the commonly used AED whichinclude dizziness, blurred vision, nausea, respiratory systemdepression, tiredness, headaches, and other motor side effects on thecentral nervous system. These side effects are particularly common ashigher doses or combinations of numerous AED are used. As such there isa need for an alternative medication that is able to reduce the numbersof seizures whilst at the same time exhibiting a safe side effectprofile.

Preferably the dose of CBD is greater than 5 mg/kg/day. Thus for a 15 kgpatient a dose of greater than 75 mg of CBD per day would be provided.Doses greater than 5 mg/kg/day such as greater than 10/mg/kg/day,greater than 15 mg/kg/day, greater than 20 mg/kg/day and greater than 25mg/kg/day are also envisaged to be effective.

In accordance with a second aspect of the present invention there isprovided a method of treating focal seizures in Dravet Syndromecomprising administering cannabidiol (CBD) to a subject.

Preferably the subject is a human.

In accordance with a third aspect of the present invention there isprovided a composition for use in the treatment of epilepsycharacterised by focal seizures in Dravet syndrome comprisingcannabidiol (CBD), a solvent, a co-solvent, a sweetener, and aflavouring.

Preferably the solvent is sesame oil, the co-solvent is ethanol, thesweetener is sucralose, the flavouring is strawberry flavour and the CBDis present at a concentration of between 25/mg/ml and 100 mg/ml, namely50 mg/ml and 75 mg/ml.

More preferably the composition comprises cannabidiol (CBD) at aconcentration of between 25 to 100 mg/ml, ethanol at a concentration of79 mg/ml, sucralose at a concentration of 0.5 mg/ml, strawberryflavouring at a concentration of 0.2 mg/ml and sesame oil q.s. to 1.0ml.

It is envisaged that the composition be administered as an oral liquidsolution. Other modes of administration including solids, semi-solids,gels, sprays, aerosols, inhalers, vaporisers, enemas and suppositoriesare alternative administration forms. Such medicaments could beadministered via the oral, buccal, sublingual, respiratory, nasal anddistal rectum route.

Definitions

Definitions of some of the terms used to describe the invention aredetailed below:

The cannabinoids described in the present application are listed belowalong with their standard abbreviations.

TABLE 4 Cannabinoids and their abbreviations CBD Cannabidiol

CBDA Cannabidiolic acid

CBDV Cannabidivarin

CBDVA Cannabidivarinic acid

THC Tetrahydrocannabinol

The table above is not exhaustive and merely details the cannabinoidswhich are identified in the present application for reference. So farover 60 different cannabinoids have been identified and thesecannabinoids can be split into different groups as follows:Phytocannabinoids; Endocannabinoids and Synthetic cannabinoids (whichmay be novel cannabinoids or synthetically produced phytocannabinoids orendocannabinoids).

“Phytocannabinoids” are cannabinoids that originate from nature and canbe found in the cannabis plant. The phytocannabinoids can be isolatedfrom plants to produce a highly purified extract or can be reproducedsynthetically.

“Highly purified cannabinoid extracts” are defined as cannabinoids thathave been extracted from the cannabis plant and purified to the extentthat other cannabinoids and non-cannabinoid components that areco-extracted with the cannabinoids have been substantially removed, suchthat the highly purified cannabinoid is greater than or equal to 98%(w/w) pure.

“Synthetic cannabinoids” are compounds that have a cannabinoid orcannabinoid-like structure and are manufactured using chemical meansrather than by the plant.

Phytocannabinoids can be obtained as either the neutral (decarboxylatedform) or the carboxylic acid form depending on the method used toextract the cannabinoids. For example it is known that heating thecarboxylic acid form will cause most of the carboxylic acid form todecarboxylate into the neutral form.

“Treatment-resistant epilepsy” (TRE) or “intractable epilepsy” isdefined as per the ILAE guidance of 2009 as epilepsy that is notadequately controlled by trials of one or more AED.

“Childhood epilepsy” refers to the many different syndromes and geneticmutations that can occur to cause epilepsy in childhood. Examples ofsome of these are as follows: Dravet Syndrome; Myoclonic-AbsenceEpilepsy; Lennox-Gastaut syndrome; Generalized Epilepsy of unknownorigin; CDKL5 mutation; Aicardi syndrome; bilateral polymicrogyria;Dup15q; SNAP25; and febrile infection related epilepsy syndrome (FIRES);benign rolandic epilepsy; juvenile myoclonic epilepsy; infantile spasm(West syndrome); and Landau-Kleffner syndrome. The list above isnon-exhaustive as many different childhood epilepsies exist.

“Focal Seizures” are defined as seizures which originate within networkslimited to only one hemisphere. What happens during the seizure dependson where in the brain the seizure happens and what that part of thebrain normally does.

“Focal seizure where awareness/consciousness are impaired” has replacedthe term “complex partial seizure”. These seizures usually start in asmall area of the temporal lobe or frontal lobe of the brain and involveother areas of the brain within the same hemisphere that affectalertness and awareness. Most subjects experience automatisms during afocal seizure with impaired consciousness.

“Mixed seizures” are defined as the existence of both generalised andfocal seizures in the same patient.

The terms “50% responder” and “50% reduction in seizure” are both termsused in clinical studies. In the present application the terms definethe percentage of subjects that experienced a greater than or equal to50% reduction in the number of seizures during treatment with CBD incomparison to the number experienced during the baseline period beforethe CBD was administered.

DETAILED DESCRIPTION

Preparation of Highly Purified CBD Extract

The following describes the production of the highly-purified (>98% w/w)cannabidiol extract which has a known and constant composition which wasused for the expanded access trials described in the Examples below.

In summary the drug substance used in the trials is a liquid carbondioxide extract of high-CBD containing chemotypes of Cannabis sativa L.which had been further purified by a solvent crystallization method toyield CBD. The crystallisation process specifically removes othercannabinoids and plant components to yield greater than 98% CBD.

The Cannabis sativa L. plants are grown, harvested, and processed toproduce a botanical extract (intermediate) and then purified bycrystallization to yield the CBD (drug substance).

The plant starting material is referred to as Botanical Raw Material(BRM); the botanical extract is the intermediate; and the activepharmaceutical ingredient (API) is CBD, the drug substance.

Both the botanical starting material and the botanical extract arecontrolled by specifications. The drug substance specification isdescribed in Table 1 below.

TABLE 5 CBD Specification Test Test Method Limits Appearance VisualOff-white/pale yellow crystals Identification A HPLC-UV Retention timeof major peak corresponds to certified CBD Reference StandardIdentification B GC-FID/MS Retention time and mass spectrum of majorpeak corresponds to certified CBD Reference Standard Identification CFT-IR Conforms to reference spectrum for certified CBD ReferenceStandard Identification D Melting 65-67° C. Point Identification ESpecific Conforms with certified CBD Optical Reference Standard; −110°Rotation to −140° (in 95% ethanol) Total Purity Calculation ≥98.0%Chromatographic Purity HPLC-UV ≥98.0% 1 Chromatographic Purity GC-FID/MS≥98.0% 2 Other Cannabinoids: HPLC-UV CBDA NMT 0.15% w/w CBDV NMT 1.0%w/w Δ⁹ THC NMT 0.15% w/w CBD-C4 NMT 0.5% w/w Residual Solvents: GCAlkane NMT 0.5% w/w Ethanol NMT 0.5% w/w Residual Water Karl Fischer NMT1.0% w/w NMT—Not more than

The purity of the CBD drug substance achieved is greater than 98%. Theother cannabinoids which may occur in the extract are: CBDA, CBDV,CBD-C4 and THC.

Distinct chemotypes of Cannabis sativa L. plant have been produced tomaximize the output of the specific chemical constituents, thecannabinoids. One type of plant produces predominantly CBD. Only the(−)-trans isomer occurs naturally. Furthermore during purification thestereochemistry of CBD is not affected.

Production of the Intermediate

An overview of the steps to produce a botanical extract, theintermediate, are as follows:

-   -   1. Growing    -   2. Decarboxylation    -   3. Extraction No. 1—using liquid CO₂    -   4. Extraction No. 2—‘winterization’ using ethanol    -   5. Filtration    -   6. Evaporation

High CBD chemovars were grown, harvested and dried and stored in a dryroom until required. The botanical raw material (BRM) was finely choppedusing an Apex mill fitted with a 1 mm screen. The milled BRM was storedin a freezer for up to 3 months prior to extraction.

Decarboxylation of CBDA to CBD was carried out using a large Heraeustray oven. The decarboxylation batch size in the Heraeus isapproximately 15 Kg. Trays were placed in the oven and heated to 105°C.; the BRM took 96.25 minutes to reach 105° C. Held at 105° C. for 15Minutes. Oven then set to 150° C.; the BRM took 75.7 minutes to reach150° C.; BRM held at 150° C. for 130 Minutes. Total time in the oven was380 Minutes, including 45 minutes cooling and 15 Minutes venting.

Extraction No 1 was performed using liquid CO₂ at 60 bar/10° C. toproduce botanical drug substance (BDS).

The crude CBD BDS was winterised in Extraction No 2 under standardconditions (2 volumes of ethanol at minus 20° C. for around 50 hours).The precipitated waxes were removed by filtration and the solventevaporated using the rotary evaporator (water bath up to 60° C.) toyield the BDS, which was then used for crystallisation to produce thetest material.

Production of the Drug Substance

The manufacturing steps to produce the drug substance from theintermediate botanical extract are as follows:

-   -   1. Crystallization using C5-C12 straight chain or branched        alkane    -   2. Filtration    -   3. Optional recrystallization from C5-C12 straight chain or        branched alkane    -   4. Vacuum drying

Intermediate botanical extract (12 kg) produced using the methodologyabove was dispersed in C5-C12 straight chain or branched alkane (9000ml, 0.75 vols) in a 30 liter stainless steel vessel.

The mixture was manually agitated to break up any lumps and the sealedcontainer then placed in a freezer for approximately 48 hours.

The crystals were isolated by vacuum filtration, washed with aliquots ofcold C5-C12 straight chain or branched alkane (total 12000 ml), anddried under a vacuum of <10 mb at a temperature of 60° C. until drybefore submitting the drug substance for analysis.

The dried product was stored in a freezer at minus 20° C. in apharmaceutical grade stainless steel container, with FDA food gradeapproved silicone seal and clamps.

Production of the Drug Product

The drug product is presented as an oral solution. The oral solutionpresentation contains 25 mg/ml or 100 mg/ml CBD, with the excipientssesame oil, ethanol, sucralose and flavouring. Two product strengths areavailable to allow dose titration across a wide dose range.

The 25 mg/ml solution is appropriate at lower doses and the 100 mg/mlsolution at higher doses.

The drug product formulation is as described in Table 6 below.

TABLE 6 Drug Product specification Reference Qualitative to QualityComponent Composition Function Standard Cannabidiol (CBD) 25 mg/ml or100 mg/ml Active In-house Anhydrous ethanol 79.0 mg/ml* Excipient Ph.Eur. Sucralose 0.5 mg/ml Sweetener In-house Strawberry 0.2 mg/mlFlavouring In-house flavouring Sesame oil q.s to 1.0 ml Excipient Ph.Eur.

The drug substance, CBD is insoluble in water. Sesame oil was selectedas an excipient to solubilize the drug substance.

A sweetener and fruit flavouring are required to improve palatability ofthe sesame oil solution.

Ethanol was required to solubilize the sweetener and the flavouring.

The composition can be substantially equivalent, by which is meant thefunctional ingredients can vary from the qualitative compositionspecified in Table 6 by an amount of up to 10%.

Example 1 below describes the use of a highly purified cannabis extractcomprising cannabidiol (CBD). Cannabidiol is the most abundantnon-psychoactive cannabinoid in the selected chemovar. Previous studiesin animals have demonstrated that CBD has anticonvulsant efficacy inmultiple species and models.

Example 1 describes data produced in an expanded access treatmentprogram in children with TRE.

EXAMPLE 1 Efficacy of Cannabidiol Reducing Focal Seizures in Childrenand Young Adults with Intractable Epilepsy

Materials and Methods

Of 137 children and young adults with severe, childhood onsettreatment-resistant epilepsy (TRE), fifty-one suffered from epilepsythat was characterised by focal seizures. These subjects were testedwith a highly purified extract of cannabidiol (CBD) obtained from acannabis plant. All subjects presented with focal type seizures, oftenin addition to generalised seizures. The participants in the study werepart of an expanded access compassionate use program for CBD.

The epileptic syndromes that these patients suffered from were asfollows: Lennox-Gastaut Syndrome; Tuberous Sclerosis Complex; DravetSyndrome; CDKL5; Neuronal ceroid lipofuscinoses (NCL); febrile infectionrelated epilepsy syndrome (FIRES); Aicardi syndrome and brainabnormalities.

Other seizure types experienced by these patients included: tonic,clonic, tonic-clonic, myoclonic, atonic, absence, myoclonic-absence,focal seizures without impairment, focal seizures with impairment andfocal seizures evolving to bilateral convulsive seizures.

All patients entered a baseline period of 4 weeks whenparents/caregivers kept prospective seizure diaries, noting allcountable seizure types.

The patients then received a highly purified CBD extract (greater than98% CBD w/w) in sesame oil, of known and constant composition, at a doseof 5 mg/kg/day in addition to their baseline anti-epileptic drug (AED)regimen.

The daily dose was gradually increased by 2 to 5 mg/kg increments untilintolerance occurred or a maximum dose of 25 mg/kg/day was achieved.

Patients were seen at regular intervals of 2-4 weeks. Laboratory testingfor hematologic, liver, kidney function and concomitant AED levels wasperformed at baseline, and after every 4 weeks of CBD therapy.

The patients on the study were all taking at least one concomitant AED.These included: carbamezapine, clobazam, clonazepam, clonidine,clorazepate, desmethylclobazam, diazepam, ethosuximide, felbamate,ketogenic diet, lacosamide, lamotrigine, levetiracetam, lorazepam,midazolam, N-desmethylclobazam, nordiazepam, oxycarbamezapine,perampanel, phenobarbital, phenytoin, pregabalin, rufinamide,stiripentol, topiramate, trazodone, vagus nerve stimulation, valproicacid, vigabatrin, and zonisamide.

Results

The 51 children and young adult patients all of whom suffered from focalseizures received treatment with CBD who received treatment for at least12 weeks.

A summary of the 50% responders, based on 12 weeks of treatment aresummarized in Table 7 below.

TABLE 7 Summary of 50% responders after 12 weeks of treatment for focalseizures Focal seizures Total seizures (n = 51) (n = 137) >50% reductionin 63% (n = 32) 46% (n = 63) seizures <50% reduction in 37% (n = 19) 54%(n = 74) seizures

Table 7 shows that after 3 months of therapy, a remarkable 63% ofpatients had an equal to or greater than >50% reduction in focalseizures, these data infer that the CBD is very effective at reducingthis type of seizure.

Conclusions

These data indicate that CBD significantly reduces the number of focalseizures in a high proportion of patients that do not respond well toexisting AED.

It was surprising that in this group of patients which aretreatment-resistant such a high number were able to gain an effect. Thefact that nearly two thirds of the patients (63%) benefitted from atleast a fifty percent reduction in the number of focal seizures thatthey suffered from was remarkable.

EXAMPLE 2 Efficacy of Cannabidiol Reducing Focal Seizures withImpairment in Children and Young Adults with Intractable Epilepsy

Materials and Methods

Of 137 children and young adults with severe, childhood onsettreatment-resistant epilepsy (TRE), thirty-seven suffered from epilepsythat was characterised by focal seizures with impairment. These subjectswere tested with a highly purified extract of cannabidiol (CBD) obtainedfrom a cannabis plant. All subjects presented with focal seizures withimpairment, often in addition to other generalised and/or focalseizures. The participants in the study were part of an expanded accesscompassionate use program for CBD.

The epileptic syndromes that these patients suffered from were asfollows: Lennox-Gastaut Syndrome; Tuberous Sclerosis Complex; DravetSyndrome; CDKL5; febrile infection related epilepsy syndrome (FIRES);Aicardi syndrome and brain abnormalities.

All patients entered a baseline period of 4 weeks whenparents/caregivers kept prospective seizure diaries, noting allcountable seizure types.

The patients then received a highly purified CBD extract (greater than98% CBD w/w) in sesame oil, of known and constant composition, at a doseof 5 mg/kg/day in addition to their baseline anti-epileptic drug (AED)regimen.

The daily dose was gradually increased by 2 to 5 mg/kg increments untilintolerance occurred or a maximum dose of 25 mg/kg/day was achieved.

Patients were seen at regular intervals of 2-4 weeks. Laboratory testingfor hematologic, liver, kidney function and concomitant AED levels wasperformed at baseline, and after every 4 weeks of CBD therapy.

The patients on the study were all taking at least one concomitant AED.These included: carbamezapine, clobazam, clonazepam, clorazepate,desmethylclobazam, diazepam, ethosuximide, felbamate, ketogenic diet,lacosamide, lamotrigine, levetiracetam, lorazepam, midazolam.N-desmethylclobazam, nordiazepam, oxycarbamezapine, perampanel,phenobarbital, phenytoin, pregabalin, rufinamide, topiramate, vagusnerve stimulation, valproic acid, vigabatrin, and zonisamide.

Results

The 37 children and young adult patients all of whom suffered from focalseizures with impairment received treatment with CBD who receivedtreatment for at least 12 weeks.

A summary of the 50% responders, based on 12 weeks of treatment aresummarized in Table 8 below.

TABLE 8 Summary of 50% responders after 12 weeks of treatment for focalseizures with impairment Focal Seizures with Total seizures Impairment(n = 37) (n = 137) >50% reduction in 65% (n = 24) 46% (n = 63) seizures<50% reduction in 35% (n = 13) 54% (n = 74) seizures

Table 8 shows that after 3 months of therapy, a remarkable 65% ofpatients had an equal to or greater than >50% reduction in focalseizures with impairment, these data infer that the CBD is veryeffective at reducing this type of seizure.

Furthermore when these data are compared to the other sub-types of focalseizure, namely focal seizure without impairment and focal seizuresleading to secondary generalisation it can clearly be seen that CBD wasable to selectively reduce the occurrence of focal seizures withimpairment. Table 9 below details these findings.

TABLE 9 Summary of 50% responders after 12 weeks of treatment for allfocal seizure types Focal Focal Focal Seizures Seizures Seizures Leadingto Total with without Secondary Focal Impairment Impairment Generalisedseizures (n = 37) (n = 6) (n = 15) (n = 51) >50% reduction 65% 50% 47%63% in seizures (n = 24) (n = 3) (n = 7) (n = 32) <50% reduction 35% 50%53% 37% in seizures (n = 13) (n = 3) (n = 8) (n = 19)

Conclusions

These data indicate that CBD significantly reduces the number of focalseizures with impairment in a selective manner.

It was surprising that in this group of patients which aretreatment-resistant such a high number were able to gain an effect. Thefact that over two thirds of the patients (65%) benefitted from at leasta fifty percent reduction in the number of focal seizures withimpairment that they suffered from was remarkable.

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The invention claimed is:
 1. A method of treating focal seizures inDravet Syndrome, comprising administering to a subject in need thereofcannabidiol (CBD), wherein the CBD has a purity of at least 98% (w/w)and comprises no more than 0.15% (w/w) Δ9-tetrahydrocannabidiol, whereinthe CBD is administered at a dose of from 15 mg/kg/day to 20 mg/kg/day.2. The method of claim 1, wherein the focal seizures are focal seizureswith impairment.
 3. The method of claim 1, wherein the Dravet Syndromeis treatment-resistant.
 4. The method of claim 1, wherein the CBD isadministered in combination with one or more concomitant anti-epilepticdrugs (AED).
 5. The method of claim 1, wherein the CBD is a highlypurified extract of cannabis.
 6. The method of claim 5 wherein thehighly purified extract further comprises up to 1% cannabidivarin(CBDV).
 7. The method of claim 1, wherein the CBD is present as asynthetic compound.
 8. The method of claim 4, wherein the one or moreAED is selected from the group consisting of: carbamezapine, clobazam,clonazepam, clonidine, clorazepate, desmethylclobazam, diazepam,ethosuximide, felbamate, ketogenic diet, lacosamide, lamotrigine,levetiracetam, lorazepam, midazolam, N-desmethylclobazam, nordiazepam,oxycarbamezapine, perampanel, phenobarbital, phenytoin, pregabalin,rufinamide, stiripentol, topiramate, trazodone, vagus nerve stimulation,valproic acid, vigabatrin, and zonisamide.
 9. The method of claim 1,wherein the CBD is administered as an oral composition comprisingcannabidiol (CBD), a solvent, a co-solvent, a sweetener, and aflavouring.
 10. The method of claim 9, wherein the solvent is sesameoil.
 11. The method of claim 9, wherein the co-solvent is ethanol. 12.The method of claim 9, wherein the sweetener is sucralose.
 13. Themethod of claim 9, wherein the flavouring is strawberry flavour.
 14. Themethod of claim 9, wherein the CBD is present at a concentration ofbetween 25 mg/ml and 100 mg/ml.
 15. The method of claim 9, wherein thecomposition comprises cannabidiol (CBD) at a concentration of between 25to 100 mg/ml, ethanol as co-solvent at a concentration of 79 mg/ml,sucralose as sweetener at a concentration of 0.5 mg/ml, strawberryflavouring as flavouring at a concentration of 0.2 mg/ml, and sesame oilas solvent q.s. to 1.0 ml.
 16. A method of treating focal seizures inDravet Syndrome, comprising administering to a subject in need thereofcannabidiol (CBD), wherein the CBD has a purity of at least 98% (w/w)and comprises no more than 0.15% (w/w) Δ9-tetrahydrocannabidiol, whereinthe CBD is administered at a dose of 20 mg/kg/day.
 17. The method ofclaim 16, wherein the focal seizures are focal seizures with impairment.18. The method of claim 16, wherein the Dravet Syndrome istreatment-resistant.
 19. The method of claim 16, wherein the CBD isadministered in combination with one or more concomitant anti-epilepticdrugs (AED).
 20. The method of claim 16, wherein the CBD is a highlypurified extract of cannabis.
 21. The method of claim 20, wherein thehighly purified extract further comprises up to 1% cannabidivarin(CBDV).
 22. The method of claim 16, wherein the CBD is present as asynthetic compound.
 23. The method of claim 19, wherein the one or moreAED is selected from the group consisting of: carbamezapine, clobazam,clonazepam, clonidine, clorazepate, desmethylclobazam, diazepam,ethosuximide, felbamate, ketogenic diet, lacosamide, lamotrigine,levetiracetam, lorazepam, midazolam, N-desmethylclobazam, nordiazepam,oxycarbamezapine, perampanel, phenobarbital, phenytoin, pregabalin,rufinamide, stiripentol, topiramate, trazodone, vagus nerve stimulation,valproic acid, vigabatrin, and zonisamide.
 24. The method of claim 16,wherein the CBD is administered as an oral composition comprisingcannabidiol (CBD), a solvent, a co-solvent, a sweetener, and aflavouring.